U.S. patent number 7,473,255 [Application Number 11/349,559] was granted by the patent office on 2009-01-06 for transbuccal plate holding cannula.
This patent grant is currently assigned to Synthes (U.S.A.). Invention is credited to Robert Joseph Chilton, III, Paul Christopher Ciccone, Dana Joseph Coombs, Bryan James Griffiths, Ross Jonathan Hamel, Owen Carlos McGarity.
United States Patent |
7,473,255 |
McGarity , et al. |
January 6, 2009 |
Transbuccal plate holding cannula
Abstract
The present invention relates to a transbuccal plate holding
cannula used in osteofixation procedures. The transbuccal plate
holding cannula of the present invention can be releasibly secured
to a bone plate such that tools and fasteners may be passed through
the plate holding cannula in order to secure the bone plate to a
bone.
Inventors: |
McGarity; Owen Carlos
(Swarthmore, PA), Griffiths; Bryan James (Coatesville,
PA), Ciccone; Paul Christopher (Lincoln University, PA),
Hamel; Ross Jonathan (West Chester, PA), Coombs; Dana
Joseph (Harleysville, PA), Chilton, III; Robert Joseph
(Quakertown, PA) |
Assignee: |
Synthes (U.S.A.) (West Chester,
PA)
|
Family
ID: |
38330526 |
Appl.
No.: |
11/349,559 |
Filed: |
February 8, 2006 |
Prior Publication Data
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|
|
|
Document
Identifier |
Publication Date |
|
US 20070213726 A1 |
Sep 13, 2007 |
|
Current U.S.
Class: |
606/86B |
Current CPC
Class: |
A61B
17/1728 (20130101); A61B 17/808 (20130101); A61B
17/8071 (20130101) |
Current International
Class: |
A61B
17/56 (20060101) |
Field of
Search: |
;606/86,110,113,114,127,86R,86A,86B,99,102-105.5,91,101
;623/17.17,17.18 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Robert; Eduardo C
Assistant Examiner: Rust; Ellen
Attorney, Agent or Firm: Woodcock Washburn LLP
Claims
What is claimed:
1. An apparatus for holding a bone plate comprising: a tubular
member comprising: a cylindrical body having a front end and a rear
end; a tip opening in said front end; a rear opening in said rear
end; a passageway in said body extending from said tip opening to
said rear opening; at least two longitudinal slots disposed at said
front end of said cylindrical body and around a circumference of
said front end of said cylindrical body and extending axially
rearward from said front end, at least a portion of said slots
extending through said cylindrical body such that said slots form
an opening to said passageway; a flange disposed around said rear
opening; an inner sleeve being slideably disposed inside said
passageway of said tubular member, said inner sleeve comprising: a
front end; a back end; and a flange disposed around said back end;
at least two substantially longitudinal fingers extending from said
front end of said inner sleeve, said fingers being aligned with
said longitudinal slots in said front end of said tubular member;
whereby said fingers extend axially forward and radially outward as
said inner sleeve slides forward in said tubular member, and
wherein said fingers retract axially rearward and radially inward
as said inner sleeve slides backward in said tubular member; and
tips being formed at a distal end of said fingers and bent radially
inward.
2. The apparatus of claim 1, wherein said tips engage said outer
periphery of said bone plate against said front end of said tubular
member as said fingers retract.
3. The apparatus of claim 1 further comprising a spring being
disposed around said inner sleeve, between said flange of said
tubular member and said flange of said inner sleeve.
4. The apparatus of claim 1, wherein said slots further comprise
ramps, wherein said ramps slope radially outward in a longitudinal
direction from said back end toward said front end.
5. The apparatus of claim 1, wherein said tubular member further
comprises recesses located at said front end of said cylindrical
body and on an outer surface of said cylindrical body such that
said tips engage said recesses when said fingers are in a retracted
position.
6. The apparatus of claim 1, wherein said front end of said tubular
member further comprises a chamfered edge around an outer surface
of said tip opening.
7. The apparatus of claim 1, further comprising a rod, said rod
comprising: a body having a front end and a back end; a tapered tip
on said front end; and a flange disposed around said back end;
wherein said rod is slideably inserted into a passageway extending
through said inner sleeve such that said flange on said back end of
said rod rests on said flange on said back end of said inner
sleeve.
8. The apparatus of claim 1, further comprising a handle, said
handle comprising an annular opening, wherein said tubular member
is inserted through said annular opening and secured to said
handle.
9. The apparatus of claim 8, further comprising a ratchet mechanism
for actuating the forward, sliding movement of said inner sleeve
relative to said tubular member.
10. An apparatus for holding a bone plate comprising: (a) a tubular
member comprising: a body having a front end and a rear end; a tip
opening in said front end; a rear opening in said rear end; a
passageway in said body extending from said tip opening to said
rear opening; at least two longitudinal slots disposed at said
front end of said body and around a periphery of said front end of
said body and extending longitudinally rearward from said front
end, at least a portion of said slots extending through said body
such that said slots form an opening to said passageway; and a
flange disposed around said rear opening; and (b) an inner sleeve
being slideably disposed inside said passageway of said tubular
member, said inner sleeve comprising: a front end; a back end; a
flange disposed around said back end; at least two substantially
longitudinal fingers extending from said front end of said inner
sleeve, said fingers being aligned with said longitudinal slots in
said front end of said tubular member; and finger tips being formed
at a distal end of said fingers and bent radially inward; whereby
said fingers extend longitudinally forward and radially outward as
said inner sleeve slides forward in said tubular member, and
wherein said fingers retract longitudinally rearward and radially
inward as said inner sleeve slides backward in said tubular
member.
11. The apparatus of claim 10, wherein said finger tips engage said
outer periphery of said bone plate against said front end of said
tubular member as said fingers retract.
12. The apparatus of claim 10 further comprising a spring being
disposed around said inner sleeve, between said flange of said
tubular member and said flange of said inner sleeve.
13. The apparatus of claim 10, wherein said slots further comprise
ramps, wherein said ramps slope radially outward in a longitudinal
direction from said back end toward said front end.
14. The apparatus of claim 10, wherein said tubular member further
comprises recesses on an outer surface at said front end of said
body such that said tips engage said recesses when said fingers are
in a retracted position.
15. The apparatus of claim 10, wherein said front end of said
tubular member further comprises a chamfered edge around an outer
surface of said tip opening.
16. The apparatus of claim 10, wherein said inner sleeve has an
inner passageway, and the apparatus further comprises a rod, said
rod comprising: a body having a front end and a back end; a tapered
tip on said front end; and a flange disposed around said back end;
wherein said rod is slideably inserted into said sleeve passageway
such that said flange on said back end of said rod rests on said
flange on said back end of said inner sleeve.
17. The apparatus of claim 10, further comprising a handle, said
handle comprising an annular opening, wherein said tubular member
is inserted through said annular opening and secured to said
handle.
18. The apparatus of claim 17, further comprising a ratchet
mechanism for actuating the forward, sliding movement of said inner
sleeve relative to said tubular member.
19. The apparatus of claim 10 wherein said finger tips are biased
open.
20. The apparatus of claim 10 wherein said finger tips are biased
closed.
Description
TECHNOLOGY FIELD
Generally, the invention relates to instrumentation for
osteofixation. More specifically, the invention relates to a
transbuccal plate holding cannula.
BACKGROUND
The use of plates for osteofixation is well known. Plates are used
to stabilize, mend, or align a patient's bone. Fasteners such as
screws are driven through holes in the plate to secure the plate to
the bone. The bone often needs to be drilled to allow the screws to
be properly secured. The drilling is done through the holes in the
plate to ensure proper alignment of the plate on the bone. Accurate
alignment of the holes in the plate and the holes drilled in the
bone is crucial to properly affix the plate to the bone. Thus, the
plate must be maintained at a specific position on the bone while a
hole is drilled and a screw is driven into the bone.
In order to accomplish the bone drilling, a drill guide is employed
to ensure proper alignment of the plate hole with the hole drilled
in the bone. In some cases, due to limited access, it is necessary
to introduce drills and screws through a small incision in the soft
tissues covering the site of osteofixation. A cannula is inserted
into the soft tissue incision to ensure the opening is maintained,
to provide access to the bone for drills and screws, and to provide
protection for the surrounding soft tissue. Current cannula systems
allow for passage of drill guides, drills, screwdrivers, and screws
through a cannula that must be placed and held in alignment with
the holes in the plate. Alignment of such cannula systems is
accomplished by providing complementary geometry on the plate and
the tip of the cannula. This method of alignment, however, requires
constant axial pressure on the plate and is difficult to maintain.
Relying on axial pressure for alignment makes it particularly
difficult to manipulate the plate intraorally in maxillofacial
surgery. Releasing axial pressure on the plate can cause the
cannula and the plate to become misaligned with respect to the hole
being drilled in the bone.
SUMMARY
The invention provides an instrument that securely holds a plate
and allows the passage of tools and fasteners, such as drills and
screws, through the instrument to secure the plate to a bone. The
instrument allows a user to hold and manipulate a plate while
drilling and screwing the plate to a bone without having to
maintain constant axial pressure on the plate.
According to a preferred embodiment of the invention, the
instrument comprises a tubular member and a tubular inner sleeve
disposed telescopically within a central passageway in the tubular
member. Preferably, the front end of the tubular member is made to
self align with the plate by providing matching chamfered edges on
the tubular member and holes in the plate. When the front end of
the tubular member is aligned with a hole in the plate, the
instrument can engage and hold the plate.
The inner sleeve has fingers extending from its front end. In one
embodiment, the fingers are bent such that they extend radially
outward and longitudinally forward from the front end of the inner
sleeve. Further, the fingers have tips on their forward ends that
are bent radially inward and transverse to the fingers.
According to a preferred embodiment, the inner sleeve is slidably
disposed within the tubular member such that the fingers extend
radially outward and axially forward through longitudinal slots in
the tubular member when the back end of the inner sleeve is pressed
forward. When the back end of the inner sleeve is released, the
inner sleeve can slide back and the fingers can retract. The tips
of the fingers may engage recesses on an outer surface of the
tubular member in order to secure the inner sleeve to the tubular
member. In one embodiment, a spring inside the tubular member
causes the inner sleeve to slide back. The fingers extend and
retract to securely engage the outer periphery of the plate while
drills and screws are introduced through the inner sleeve. Once the
instrument has engaged the plate, drills and screws can be
introduced through the inner sleeve to secure the plate to the
bone.
According to another aspect of the invention, the rear surface of
the bone plate has recesses formed on the periphery of the plate
close to the plate holes to further facilitate engagement of the
plate by the fingers. The recesses on the back surface of the plate
allow the plate holding instrument to position the plate
substantially flush against the bone while the plate is being
secured to the bone and allow the fingers to freely disengage after
the plate has been secured to the bone.
According to another aspect of the invention, a rod is provided to
be slidably inserted through a central passageway in the inner
sleeve such that the front tip of the rod protrudes through a tip
opening on the front end of the tubular member. Preferably, the
front end of the rod tapers to a point so that when it protrudes
through the tip opening of the tubular member, the front end of the
tubular member can be more easily inserted and guided through an
incision in the body.
In another embodiment, the fingers of the inner sleeve extend
outwardly from the tubular member through the tip opening rather
than through longitudinal slots on the front end of the tubular
member. In this embodiment, the fingers are biased to expand
radially outward as they are extended axially forward. Further, the
tips of the fingers are bent radially outward to engage the inner
periphery of the plate holes rather than the outer periphery of the
plate while still allowing the passage of drills and screws through
the inner sleeve.
According to another aspect of the invention, the bone plate has
recesses formed adjacent to the plate holes to accept the fingers
of the plate holding instrument. In one embodiment, the recesses
extend alongside the plate holes and radially outward from the
center of the plate holes. The recesses allow the fingers to engage
the plate hole while still allowing drills and screws to freely
pass through the plate holes.
Additional features and advantages of the invention will be made
apparent from the following detailed description of illustrative
embodiments that proceeds with reference to the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing summary, as well as the following detailed
description of the preferred embodiments, is better understood when
read in conjunction with the appended drawings. For the purpose of
illustrating the invention, there is shown in the drawings
embodiments that are presently preferred, it being understood,
however, that the invention is not limited to the specific methods
and instrumentalities disclosed. In the drawings:
FIG. 1 shows an exemplary plate holding instrument;
FIG. 2A shows a top view of an exemplary bone plate;
FIG. 2B shows a side view of an exemplary bone plate;
FIG. 2C shows a cross sectional view of an exemplary bone plate
taken along sectional line 2C-2C of FIG. 2B;
FIG. 3 shows an exemplary tubular member;
FIG. 4A shows an exemplary inner sleeve;
FIG. 4B shows another exemplary embodiment of the inner sleeve;
FIG. 5 shows an exemplary rod;
FIG. 6 shows a partially exploded view of an exemplary plate
holding instrument;
FIG. 7 shows an exemplary plate holding instrument having a handle
and the fingers extended;
FIG. 8 shows an exemplary plate holding instrument having a handle
and the fingers retracted;
FIG. 9 shows an exemplary plate holding instrument having a handle
and holding an exemplary bone plate;
FIG. 10 shows a cross sectional view of the front end of an
exemplary plate holding instrument;
FIG. 11 shows a cross sectional view of the front end of an
exemplary plate holding instrument with the fingers extended over
an exemplary bone plate;
FIG. 12 shows a cross sectional view of the front end of an
exemplary plate holding instrument engaging an exemplary bone
plate;
FIG. 13A shows a cross sectional view of the front end of another
exemplary embodiment of the plate holding instrument and another
exemplary embodiment of the bone plate; and
FIG. 13B shows a cross sectional view of the front end of the
exemplary plate holding instrument of FIG. 13A engaging the bone
plate.
DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
The present invention relates to instrumentation for osteofixation.
More particularly, the invention relates to specially configured
bone plates and instruments for holding bone plates during
osteofixation procedures. A plate holding instrument 1 allows a
user to securely hold a bone plate 2 to the bone while passing
drills and screws through the bone plate 2.
In a preferred embodiment, the plate holding instrument 1 is a
transbuccal plate holding cannula and the bone plate 2 is a
mandible plate. A transbuccal plate holding cannula is used to
rigidly capture a mandible plate intraorally, to manipulate plate
placement, and to accurately pass drills and screws through the
cannula into the plate. FIG. 1 shows a preferred embodiment of the
plate holding instrument 1. FIGS. 2A-2C show a preferred embodiment
of the bone plate 2. As shown in FIGS. 1 and 6, the plate holding
instrument 1 includes a tubular member 3, an inner sleeve 4, and a
rod 5.
As shown in FIGS. 2A-2C, a plate 2 includes a front surface 20, a
rear surface 21, and at least one plate hole 22. The plate hole 22
extends through the plate 2 from the front surface 20 to the rear
surface 21. Preferably, the periphery of the plate hole 22 on the
front surface 20 of the plate 2 has a chamfered surface 23. In one
embodiment, the outer periphery of the bone plate 2 on the rear
surface 21 includes recesses 25.
FIG. 3 shows an exemplary tubular member 3. As shown in FIG. 3, the
tubular member 3 has a hollow, cylindrical body 30, a front end 31,
and a rear end 32. The front end 31 has a tip opening 33a, at least
two longitudinal slots 34 and at least two recesses 35 (only one is
depicted) located around the circumference of the tubular member 3.
Preferably, the outer surface 36 of the tip opening 33a is
chamfered inwardly. As shown, the slots 34 extend from the tip
opening 33a rearward along the longitudinal length of the body 30
of the tubular member 3. The forward surface of the slots 34 have
ramps 37 that slope radially outward moving forward from the back
end toward the front end. The recesses 35 are aligned with the
slots 34 along the longitudinal axis of the tubular member 3 and
are located longitudinally forward of the slots 34. The recesses 35
extend to the tip of the front end 31 of the tubular member 3. The
rear end 32 of the tubular member 3 has an annular flange 38 and a
rear opening 33b. A passageway 39 connects the tip opening 33a on
the front end of the tubular member 3 to the rear opening 33b.
FIGS. 4A and 4B show exemplary inner sleeves 4. As shown in FIGS.
4A and 4B, the inner sleeve 4 has a hollow, cylindrical body 40, a
front end 41, and a back end 42. There are at least two fingers 43
that extend from the front end 41 of the inner sleeve 4. The distal
ends of the fingers 43 have tips 44. In a preferred embodiment, the
tips 44 are bent radially inward, as shown in FIGS. 4A and 4B. The
front end 41 of the inner sleeve 4 has a front opening 45 and the
back end 42 of the inner sleeve 4 has a back opening 46. As shown
in FIGS. 4A and 4B, the back end 42 of the inner sleeve 4 has an
annular flange 47. In an embodiment shown in FIG. 4A, the fingers
43 are biased toward a closed position and are in substantial
longitudinal alignment with the inner sleeve 4. In another
embodiment shown in FIG. 4B, the fingers 43 are biased radially
outward toward an open position.
FIG. 5 shows and exemplary rod 5. Preferably, the rod 5 is an
obturator. As shown in FIG. 5, the rod 5 has a body 50, an annular
flange 51, and a tip 52. Preferably, the tip 52 of the rod 5 tapers
to a blunt point.
FIG. 6 shows a preferred assembly of the plate holding instrument
1. As shown in FIG. 6, the inner sleeve 4 is inserted through the
rear opening 33b of the tubular member 3 and fits slidably therein.
When the inner sleeve 4 is inserted into the tubular member 3 and
slid forward, the fingers 43 protrude outwardly through the slots
34 of the tubular member 3, as shown in FIGS. 7 and 11. In the
embodiment of FIG. 4A, the fingers 43 are biased closed and are
forced open by the ramps 37 as the inner sleeve 4 is pressed
forward in the tubular member 3. In the embodiment of FIG. 4B, the
fingers 43 are biased open so that they extend axially outward
through the slots 34 as the inner sleeve 4 is pressed forward in
the tubular member 3.
Referring back to FIG. 6, a spring 6 is preferably located between
the annular flange 47 of the inner sleeve 4 and the annular flange
38 of the tubular member 3 so that the inner sleeve 4 automatically
slides back as it is released. In the embodiment of FIG. 4A, the
fingers 43 are biased closed so that they move toward a closed
position as the inner sleeve 4 slides back and off the ramps 37. In
the embodiment of FIG. 4B, the fingers 43 are biased open and are
forced closed by the tubular member 3 as the inner sleeve 4 slides
back in to the tubular member 3. Ramps (not shown) may be provided
on the back side of the slots to facilitate closing of the fingers.
When the inner sleeve 4 slides back, the finger tips 44 engage the
recesses 35 on the tubular member 3 and secure the inner sleeve 4
in the tubular member 3, thereby preventing the inner sleeve 4 from
sliding further axially backward and out of the tubular member 3.
Rod 5 is inserted into the back opening 46 of the inner sleeve 4,
slid forward, and locked into the inner sleeve 4.
As shown in FIGS. 7-9, a handle 7 can be attached to the body 30 of
the tubular member 3. As shown, the handle 7 has a body 70 that has
an annular opening 71 at an upper end 72. Preferably, the body 30
of the tubular member 3 is slid into the annular opening 71 of the
handle 7 and is secured therein. For example, an internal spring
loaded ball (not shown) and a corresponding mating recess (not
shown) may be used to secure the tubular member 3 to the handle 7.
The handle 7 facilitates manipulation of the plate holding
instrument 1 and allows the plate holding instrument 1 to be
manipulated with one hand.
According to another aspect of the invention, a handle 7 may
include a ratchet gear mechanism (not shown) to actuate the forward
movement of the inner sleeve 4 into the tubular member 3. The
ratchet gear mechanism may include a lever arm having a distal end
and a proximal end. The distal end of the lever arm may be in
contact with the back end 42 of the inner sleeve 4, a central
portion of the lever arm may be pivotally connected to the handle
body 70, and the distal end may protrude through the handle body 70
to form a trigger, or be mechanically connected to a trigger
mechanism. The trigger may be actuated to cause the distal end of
the lever arm to move the inner sleeve 4 forward into the tubular
member 3 in a controlled manner. The pivot point between the lever
arm and the handle body 70 may incorporate a ratchet gear such that
the forward movement of the distal end of the lever arm and the
back end 42 of the inner sleeve 4 toward the tubular member 3 may
be maintained. Further, a release mechanism may be employed to
disengage the ratchet gear and allow the distal end of the lever
arm and the back end 42 of the inner sleeve 4 to move back away
from the tubular member 3.
As shown in FIG. 7, when the back end 42 of the inner sleeve 4 is
pressed forward into the tubular member 3, the fingers 43 extend
axially forward and radially outward through the slots 34 (not
shown) of the tubular member 3. Referring to the embodiment of FIG.
11, the slots 34 have ramps 37 that force the fingers 43, which in
one embodiment shown in FIG. 4A are biased closed, to expand
radially outward through the slots as the inner sleeve 4 is pressed
axially forward. Alternatively, if the fingers 43 are biased open,
as shown in the embodiment illustrated in FIG. 4B, ramps are not
required and the slots 34 allow the fingers to extend axially
outward as the inner sleeve 4 is pressed forward in the tubular
member 3. As shown in FIG. 11, the radial expansion of the fingers
43 allows the fingers 43 to extend over and around the outer
periphery of a bone plate 2.
As shown in FIG. 8, when the back end 42 of the inner sleeve is
released and moved axially backward, the fingers 43 retract
inwardly into the tubular member 3. Referring to FIG. 12, the
retraction of the fingers 43 engages the outer periphery of a bone
plate 2. According to another aspect of the invention, referring to
FIG. 10, when the fingers 43 are retracted without engaging a plate
2, the finger tips 44 engage the recesses 35 on the tubular member
3, and the fingers 43 rest flush against the outer surface of the
tubular member 3. The recesses 35 help prevent the fingers 43 from
snagging tissue as the instrument 1 moves through incisions in the
body.
A preferred method for using the devices of the present invention
can be described with reference to FIGS. 10-12, which show a
preferred embodiment of the plate holding instrument 1 in
operation. First, a bone plate 2 is introduced into a patient's
body at the site of desired osteofixation. Then, the plate holding
instrument 1 is introduced into the body to manipulate the bone
plate 2 and facilitate the fixation of the plate 2 to the bone.
As shown in FIG. 10, a rod 5 is inserted through the inner sleeve
4, the tip 52 of the rod 5 protrudes through the tip opening 33a of
the tubular member 3. The protruding tip 52 of the rod 5 gives the
plate holding instrument 1 a tapered front end that is easier to
insert and guide through an incision in the body. Once plate
holding instrument 1 is properly positioned within the incision,
the rod 5 may be removed from the plate holding instrument 1.
Referring to FIG. 11, when a desired plate hole 22 is located, the
back end 42 (not shown) of the inner sleeve 4 is pressed forward to
extend the fingers 43 and engage the outer periphery of the bone
plate 2. When the back end 42 (not shown) of the inner sleeve 4 is
released, the inner sleeve 4 can slide back and the fingers 43 can
retract. In one embodiment as shown in FIG. 6, a spring 5 is
located between the annular flange 47 of the inner sleeve 4 and the
annular flange 38 of the tubular member 3 so that the inner sleeve
4 slides back and the fingers 43 retract automatically when the
back end 42 of the inner sleeve 4 is released. Further, the use of
spring 5 to retract the inner sleeve 4 helps to positively maintain
engagement of the plate 2 with the fingers 43.
Referring to FIG. 12, as the fingers 43 retract, the tips 44 of the
fingers 43 engage recessed portions 25 on the rear surface 21 of
the plate 2, and the front surface 20 of the plate 2 is moved
against the front end 31 of the tubular member 3. The tip opening
33a of the tubular member 3 is brought into contact with the plate
2 such that the chamfered outer surface 36 of the tip opening 33a
rests against the chamfered surface 23 around the periphery of the
plate hole 22. When the plate holding instrument 1 is secured to
the bone plate 2, drills and screws, for example, can be passed
through the inner sleeve 4 to secure the bone plate 2 to the
bone.
In another embodiment, shown in FIGS. 13A and 13B, the fingers 43a
of the inner sleeve 4 engage the plate 2 through the plate holes 22
at recesses 24. Preferably, the bone plate 2 includes recesses 24
proximate the plate holes 22 and the fingers 43a extend into the
recesses 24 to engage the plate 2. As shown, the bone plate 2 has a
front surface 20, a rear surface 21, and at least one plate hole
22. The plate hole 22 extends through the plate 2 from the front
surface 20 to the rear surface 21. As shown, recess 24 includes a
first portion 24a and second portion 24b. The first portion 24a of
the recess 24 is formed on the front surface 20 of the plate 2 and
extends through the plate to the rear surface 21. The second
portion 24b of the recess 24 is located adjacent to the rear
surface 21 of the plate hole 22 and extends axially outward from a
center of the plate hole 22. As shown, recess 24 extends generally
radially outward from the front surface 20 to the rear surface
21.
In this embodiment, as shown in FIGS. 13A and 13B, the fingers 43a
of the inner sleeve 4 extend longitudinally and radially outward
from the tubular member 3 through the tip opening 33a. Preferably,
the fingers 43a are curved outwardly so that they expand radially
outward as they are extended past the end 33a. Further, the tips
44a of the fingers 43a are preferably bent radially outward to
engage the recesses 24 adjacent to the plate holes 22 as the
fingers 43a extend and expand into the bone plate 2.
In operation, the plate holding instrument 1 of FIGS. 13A and 13B
is brought into contact with the plate 2. The tip opening 33a of
the tubular member 3 contacts the periphery of the plate hole 22.
The back end 42 of the inner sleeve 4 is pressed forward and the
fingers 43a extend longitudinally and radially outward through the
tip opening 33a of the tubular member 3. When the back end 42 of
the inner sleeve 4 is pressed forward, the fingers 43a extend and
expand and the tips 44a of the fingers 43a engage the recesses 24
to secure the plate 2. In this embodiment, drills and screws may be
introduced to the bone plate 2 through the inner sleeve 4 while the
inner sleeve 4 is pressed forward and the fingers 43a are securing
the bone plate 2. When the back end 42 of the inner sleeve 4 is
released, the fingers 43a retract and the plate holding instrument
1 disengages the bone plate 2.
While systems and methods have been described and illustrated with
reference to specific embodiments, those skilled in the art will
recognize that modification and variations may be made without
departing from the principles described above and set forth in the
following claims. Accordingly, reference should be made to the
following claims as describing the scope of disclosed
embodiments.
* * * * *